Tunable tachyon mass in the PT-broken massive Thirring model
arXiv:2212.08110 · doi:10.1103/PhysRevD.108.116014
Abstract
We study the full phase diagram of a non-Hermitian PT-symmetric generalization of the paradigmatic two-dimensional massive Thirring model. Employing the non-perturbative functional renormalization-group, we find that the model hosts a regime where PT symmetry is spontaneously broken. This new phase is characterized by a relevant imaginary mass, corresponding to monstronic excitations displaying exponentially growing amplitudes for time-like intervals and tachyonic (Lieb-Robison-bound breaking, oscillatory) excitations for space-like intervals. Furthermore, since the phase manifests itself as an unconventional attractive spinodal fixed point, which is typically unreachable in finite real-life systems, we find that the effective renormalized mass reached can be tuned through the microscopic parameters of the model. Our results further predict that the new phase is robust to external gauge fields, contrary to the celebrated BKT phase in the PT unbroken sector. The gauge field then provides an effective and easy means to tune the renormalized imaginary mass through a wide range of values, and therefore the amplitude growth/oscillation rate of the corresponding excitations.
14 pages, 4 figures
References in corpus (11)
- Exact evolution equation for the effective potential
- Non-Hermitian Physics
- Topological phase transition in non-Hermitian quasicrystals
- Dynamical phase transition in the open Dicke model
- Observation of Lee-Yang zeros
- Entanglement and spin squeezing in non-Hermitian phase transitions
- UV fixed-point structure of the three-dimensional Thirring model
- Symmetries and conservation laws in non-Hermitian field theories
- The phase diagram and vortex properties of PT-symmetric non-Hermitian two-component superfluid
- Universal scaling at a pre-thermal dark state
- Functional renormalization-group approach to the Pokrovsky-Talapov model via modified massive Thirring fermion model